Paleozoic rocks structure versus Cenozoic cuesta relief along the Baltic Shield–East European Platform transect
1 Uni ver sity of Tartu, In sti tute of Ecol ogy and Earth Sci ences, Ravila 14A, 50411 Tartu, Es to nia Tuuling, I., 2017. Pa leo zoic rocks struc ture ver sus Ce no zoic cuesta re lief along the Bal tic Shield-East Eu ro pean Plat form transect. Geo log i cal Quar terly, 61 (2): 396-412, doi: 10.7306/gq.1342 Based on struc tural maps, the bed rock struc ture on the south ern slope of the Bal tic Shield is ana lysed. Gently south erly dipping (0.1-0.2°) Paleozoic lay ers from Es to nia to the
... m Es to nia to the Swed ish east coast form the Bal tic Homocline (BH). Nu mer ous monoclinal folds, forced by base ment fault ing, in duce slight vari a tions in bed rock at ti tude across the BH. Stud ies on faults ex posed in South ern Fin land sug gest that many monoclinal folds in duc ing base ment faults within the BH are of Pre cam brian or i gin and have been ac tive in pulses. The pres ent mono clines were shaped by the Cal edo nian Orog eny. Submeridional tectonic hinge-lines in duce mi nor re gional-scale changes in the struc tural set ting and con trol trends/styles of the forced folds. From the west, the BH bounds with the Bal tic-Bothnian mo bile zone that has been in ter mit tently ac tive since Mesoproterozoic times. The evolv ing Bal tic Syneclise in the Si lu rian re ar ranged the struc tural set ting typ i cal for the Or do vician Bal tic Ba sin. The Ce no zoic up lift of Scan di na via cre ated a SE-to-E-dip ping bed rock se quence around the Gotland-Öland area. As the lat ter area had a dif fer ent at ti tude than the BH, two Ce no zoic cuesta-sets started to evolve around the north ern Bal tic Proper. They both had an out let to the N-S-flow ing Eridanos River around the Gotska Sandön area, cre at ing thus two in de pend ent sec tions of the Bal tic Klint.